Kludex/starlette 1.10.0

Version 1.10.0

on GitHub

📝 Leaner URL-encoded form parsing

Starlette 1.10.0 parses URL-encoded forms with less memory and CPU, no longer drops the last field when a stream ends early, and lets you compare FormData that holds several uploads under one key.

uv pip install starlette==1.10.0

• Forms with many fields parse faster and use less memory (#3724). FormParser builds each field in the parser callbacks instead of queueing every event and replaying it. On CodSpeed, 1000 fields went from 42.8 ms to 34.9 ms and from 63.5 KB to 54.5 KB, and the max_fields limit case went from 6,880 B to 864 B.
• The last field is kept when the request stream ends without an empty chunk (#3599). The parser is now finalized once the stream is exhausted, so custom streams that never yield a final b"" no longer lose their last field.
• FormData with repeated uploads can be compared (#3619). Comparing two FormData objects with several UploadFile values under the same key used to raise TypeError.

⚠️ Behaviour changes

• Multidict equality keeps the order of values under a repeated key (#3619). Keys can still appear in any order, but QueryParams("a=1&a=2") and QueryParams("a=2&a=1") are no longer equal, matching what getlist() returns.
• starlette.formparsers.FormMessage is deprecated (#3724). The parser no longer uses it, and FormParser.messages is gone. Calling FormMessage(...) emits a StarletteDeprecationWarning.

🧭 Routing and URL generation

• Path parameter values that look like a placeholder are kept as they are (#3725). url_path_for("route", category="{id}", id="42") on /{category}/{id} now returns /{id}/42 instead of /42/42. Substitution also got faster, from 549 ns to 520 ns with two parameters and from 1,078 ns to 779 ns with five.
• Route matching does less work per request (#3665, #3722). Match members are compared by identity, cutting up to 4.9% of the instructions per dispatch in the routing benchmarks.
• WSGIMiddleware strips root_path only at a path segment boundary (#3718). A request to /application under a root_path of /app no longer becomes /lication.
• FloatConvertor reports NaN and infinity correctly (#3716). NaN was reported as a negative float.

🛡️ Middleware, responses and config

• Handled exceptions no longer keep requests alive (#3205). Starlette clears the traceback after an exception handler runs, so an exception instance reused across requests, such as a module-level HTTPException, no longer pins per-request objects in memory.
• Middlewares accept http.response.start without headers (#3721). BaseHTTPMiddleware, GZipMiddleware and SessionMiddleware default the omitted field to an empty list instead of raising KeyError.
• FileResponse ignores Range on methods other than GET and HEAD (#3679). A POST endpoint that returns a file now sends the full file, as RFC 9110 requires.
• Config strips one pair of matching outer quotes from env file values (#3720). KEY='say "hi"' now reads as say "hi" instead of say "hi.

Full changelog: 1.9.0...1.10.0